本文总结如何通过java实现邮件接口的定时发送任务。

1、邮箱服务器地址和端口

以139邮箱为例，获取服务器地址和端口。139邮箱的路径：设置-常见设置-邮箱协议设置

2、客户端配置

工具：springboot2.4.3使用maven，使用java11

pom.xml引入mail第三方工具

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-mail</artifactId>
</dependency>

application.yml配置

spring :mail:host: smtp.139.comport: 465password:  XXXXXusername: 13XXXXXX@139.comdefault-encoding: UTF-8properties:mail.smtp.auth: truemail.smtp.socketFactory.fallback : truemail.smtp.socketFactory.class : javax.net.ssl.SSLSocketFactorymail.smtp.socketFactory.port : 465mail.smtp.port : 465

3、发送邮件的util类

1）简单的文本

引入JavaMailSender，新建邮件发送util类，发送简单的文本邮件

import org.springframework.mail.javamail.JavaMailSender;@Service
public class SendmailImpl{@Autowiredprivate JavaMailSender mailSender;@Value("${spring.mail.username}")  //发送人的邮箱  比如13XXXXXX@139.comprivate String from;/*** *发送简单的文本邮件* @param title* @param content* @param email*/public void sendSimpleMail(String title,String content,String email) {SimpleMailMessage message = new SimpleMailMessage();message.setFrom(from);//发送人邮箱message.setSubject(title);//标题message.setTo(email);//对方邮箱message.setText(content);//内容mailSender.send(message);}
}

2）多个收件人

引入一个MimeMessageHelper，增加多个收件人的功能支撑

/*** *多个收件人* @param title* @param content* @param email* @throws MessagingException */public void sendBatchMai(String title,String content,String[] email) throws MessagingException {MimeMessage message = mailSender.createMimeMessage();//true表示需要创建一个multipart messageMimeMessageHelper helper = new MimeMessageHelper(message,true);helper.setFrom(from);helper.setSubject(title);helper.setText(content,true);//多个收件人List<InternetAddress> list = new ArrayList<InternetAddress>();// 不能使用string类型的类型，这样只能发送一个收件人 for(int i=0;i<email.length;i++) {list.add(new InternetAddress(email[i]));}InternetAddress[] address = list.toArray(new InternetAddress[list.size()]);message.setRecipients(Message.RecipientType.TO, address);message = helper.getMimeMessage();mailSender.send(message);}

3）文件流发附件

运用装饰器（Decorator）模式，将InputStream接口转换为InputStreamSource接口。首先将InputStream转换byte[] ，再转换为ByteArrayResource，而ByteArrayResource的接口就是InputStreamSource。

/*** 文件流发邮件* @param title 邮件标题* @param content 邮件内容* @param to  收件人* @param attachmentFilenameList  文件名的list列表* @param inputStreamList 附件文件流的list列表* @param copyto 抄送人* @throws Exception*/public void sendMailStream(String title,String content,String[] to,String attachmentFilename,List<InputStream> inputStreamList) {//true表示需要创建一个multipart messageMimeMessageHelper helper;try {MimeMessage message = mailSender.createMimeMessage();helper = new MimeMessageHelper(message,true,"utf-8");helper.setFrom(from);helper.setSubject(title);helper.setText(content,true);//启用htmlhelper.setTo(to);//文件附件if(attachmentFilename!=null) {helper.addAttachment(attachmentFilename, new ByteArrayResource(IOUtils.toByteArray(inputStreamList.get(0))));}message = helper.getMimeMessage();mailSender.send(message);} catch (MessagingException e) {// TODO Auto-generated catch block
//            logger.error(e.getLocalizedMessage());e.printStackTrace();} catch (IOException e) {// TODO Auto-generated catch block
//            logger.error(e.getLocalizedMessage());e.printStackTrace();}}

4）全家桶

包括多个收件，附件以及文件内容的支持

/*** *邮件发送全* @param title   标题* @param content 内容* @param email   发件人地址* @param file    附件* @throws Exception */public void sendMail(String title,String content,String[] email,List<File> attaches) throws Exception {MimeMessage message = mailSender.createMimeMessage();//true表示需要创建一个multipart messageMimeMessageHelper helper = new MimeMessageHelper(message,true,"utf-8");helper.setFrom(from);helper.setSubject(title);helper.setText(content,true);//文件附件if(attaches.size()>0) {for(File file : attaches) {helper.addAttachment(MimeUtility.encodeText(file.getName()), file);}}//多个收件人List<InternetAddress> list = new ArrayList<InternetAddress>();// 不能使用string类型的类型，这样只能发送一个收件人 for(int i=0;i<email.length;i++) {list.add(new InternetAddress(email[i]));}InternetAddress[] address = list.toArray(new InternetAddress[list.size()]);message.setRecipients(Message.RecipientType.TO, address);message = helper.getMimeMessage();mailSender.send(message);}